Changes in soundecology 1.3.1 (2015-12-30)
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 - Added the results for the ACI by minute to the returned list in acoustic_complexity().
 - Added a vignette to compare the ACI results between soundecology and seewave.
 - Added the argument min_freq to acoustic_complexity().


Changes in soundecology 1.3 (2015-05-02)
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 - Added the results for anthrophony and biophony to the results of ndsi().
 - Fixed an error in the manual of ndsi where it said 'left' instead of 'right'.


Changes in soundecology 1.2 (2015-01-11)
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 - Added arguments to multiple_sounds() to specify the range of time in the file to use for analysis. Fixing Issue #2.


Changes in soundecology 1.1.1 (2014-04-14)
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 - Changing the import of functions from tuneR and seewave to avoid a clash between functions with similar names.


Changes in soundecology 1.1
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 - Added a new function, measure_signals(), to select signals from spectrograms.
 - Added a new function, sound_raster(), to save spectrograms as ASCII raster files for GIS software.
 - The function ndsi() was rewritten to avoid the problem R has with for loops. Now the function subsets the data in 1-second segments and feeds the data to pwelch() using apply, reducing execution time significantly.
 - The function acoustic_evenness() was incorrectly named acoustic_eveness() in version 1.0. This has been fixed.
 - Fixed a bug in multiple_sounds() where the data was not appended to the results file correctly. This problem seems to have happened only in Windows.
 - Other small bug fixes and typos.
